Active bleeding after renal transplantation diagnosed by Tc-99m DTPA scanning

Extrarenal uptake of 99mTc-DTPA at the site of bone marrow biopsy

Unexpected iliac uptake of 99mTc-DTPA was noted in a 10-year old female referred for evaluation of renal function prior to receiving chemotherapy for relapsed acute lymphocytic leukemia. This scan finding corresponded to the site of a bone marrow biopsy performed five days earlier. X-ray of the area revealed no abnormality. It is assumed that the extrarenal uptake was due to increased vascularity at the site of recent bone marrow biopsy, most likely due to increased osteoblastic reaction in the cortex of the ilium. The patient proceeded with the bone marrow transplant and was well at follow-up six months later.

Radioisotopic evaluation of renal transplants

Owing to the noninvasive nature, ready availability, and efficacy, radionuclide studies remain widely utilized following renal transplantation for monitoring changes in the functional status and detection of detrimental complications of the grafted kidney. Whereas surgical complications, including vascular occlusion, urine extravasation, drainage obstruction, hematoma, or lymphocele formation, can often be detected effectively, specification of other underlying causes of deterioration of parenchymal function, including acute tubular necrosis (ATN), various types of rejection, and cyclosporine A nephrotoxicity (CyA-NT), frequently cannot be derived independently from the findings of a study without clinical correlation. Besides imaging, plotting of renogram or time/activity curves, numerous quantitative methods have been introduced to provide objective measurements of the blood flow, as well as to gauge the capability of concentration and excretion of the transplanted kidneys. However, the findings whether qualitative or quantitative all have overlapping zones. There is no abnormal image, graphic, or numeric index absolutely specific for any of the possible posttransplant renal parenchymal complications. The differentiation of such conditions may best be achieved through chronologic association of the sequential changes, with or without quantification, detected in serial studies with the clinical presentation and findings.